BMW automotive engine families listed as N45. Specifications below retain the source's separate family and variant labels.
Family specifications
BMW N45 engine
| Field | Reported value |
|---|---|
| Production | 2004-2011 |
| Configuration | Inline-4 |
| Displacement | 1.6 L (1,596 cc) 2.0 L (1,997 cc) |
| Cylinder bore | 84 mm (3.31 in) 85 mm (3.35 in) |
| Piston stroke | 72 mm (2.83 in) 88 mm (3.46 in) |
| Cylinder block material | Aluminium |
| Cylinder head material | Aluminium |
| Valvetrain | DOHC , with VVT |
| Fuel type | Petrol |
| Predecessor | BMW N40 |
| Successor | BMW N43 |
Variant specifications
Models
| Engine | Displacement | Power | Torque | Years |
|---|---|---|---|---|
| N45B16 | 1,596 cc (97.4 cu in) | 85 kW (114 bhp) at 6,000 rpm | 150 N⋅m (111 lb⋅ft) at 4,300 rpm | 2004-2011 |
| N45B20S | 1,997 cc (121.9 cu in) | 127 kW (170 bhp) at 7,000 rpm | 200 N⋅m (148 lb⋅ft) at 4,250 rpm | 2006 |
Recorded vehicle applications
N45B16
- 2004–2011 E81/E87 116i
- 2006–2009 E90/E91 316i
N45B20S
- 2006 E90 320si (Limited production model)
BMW automotive engine directory
Design, development and variant notes
The naturally aspirated N45 is related to the N46 but omits Valvetronic and balance shafts; it retains double-VANOS cam timing. The 2007 revision is called N45N.
N45B20S was enlarged to 1,997 cc for 320si racing homologation. N45 production continued alongside the direct-injection N43 in markets where high-sulphur fuel limited use of the latter.
Data adapted from the cited Wikipedia revision by Wikipedia contributors under CC BY-SA 4.0. Production dates and fitments reflect that revision; verify the exact engine code, market and vehicle before applying a specification.
Sources
Curated reference notes. Applicability follows the cited sources; hardware testing by this wiki is not implied.
- Wikipedia: List of BMW engines. Wikipedia contributors; CC BY-SA 4.0. Source revision oldid 1382309748; accessed 2026-11-10.
- Wikipedia: BMW N45. Wikipedia contributors; CC BY-SA 4.0. Source revision oldid 1307205247; accessed 2026-11-10.
Further Wikipedia-sourced details
The following additional information is drawn from the cited Wikipedia revision by Wikipedia contributors, available under CC BY-SA 4.0. An open-ended date reflects the source snapshot, not confirmed current production or fitment.
Additional technical and variant notes
The 1,997 cc N45B20S was developed for 320si competition homologation. The source identifies a carbon-fibre valve cover as a visible difference from other N45 versions.